JP2013075589A - Steering restoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce fluctuation of a handlebar by restoring force of an air spring and changing the restoring force in response to a traveling state.SOLUTION: A restoring device is mounted on a top bridge. A vane 31 is provided in a pressure chamber 30 of the restoring device, for partitioning it into a left chamber 32 and a right chamber 33, and is turned in conjunction with a handlebar. The left chamber 32 and the right chamber 33 are connected by a first communication path 41 for an outflow and a second communication path 42 for an inflow, and the first communication path 41 and the second communication path 42 are connected by a third communication path 43. A main valve 45 is provided in the middle of the first communication path 41. Any of a fully-closed position, a half-open position, and a fully-open position is established by a linear solenoid 46. The communication between the left chamber 32 and the right chamber 33 is interrupted in the fully-closed position. High-pressure air is compressed in the left chamber 32 or the right chamber 33 by the turning of the vane 31 in conjunction with the handlebar to form an air spring so that large restoring force is generated. In the fully-open position, the left chamber 32 and the right chamber 33 are in communication with each other so that no restoring force is generated.

Description

The present invention relates to a steering restoration device for a motorcycle or the like, and more particularly, to a device that suppresses wobbling of a steering wheel during low-speed driving and enables comfortable steering operation during high-speed driving.

Self-supporting restoration is known in which the handle shaft that has been swayed using gas is self-recovered to reduce wobbling of the handle. This device uses a bicycle handle shaft as a rotation shaft, puts this rotation shaft into a gas chamber filled with gas, divides the interior into two inner chambers, and the rotation shaft rotates when the handle fluctuates. The gas in one of the inner chambers is compressed. A repulsive force due to the compressed gas is generated in the compressed inner chamber and becomes a restoring force with respect to the rotating shaft, so that the rotating shaft attempts to return to the state before the rotating. For this reason, the wobbling of the handle can be reduced (see Patent Document 1).

JP-A-6-247370

By the way, in a motorcycle equipped with an engine and traveling in a wide speed range from a low speed to a high speed, linearity increases due to the gyro effect according to the speed. However, when driving at low speed, the gyro effect is reduced, but the self-steering (automatic steering) of the steering system with respect to the roll of the vehicle body tends to be hypersensitive, so that the vehicle body is not tilted while correcting this self-steer. The state in which the driver travels while correcting the steering angle is the steering wheel wobbling during low-speed traveling. In order to reduce the steering wheel wobbling during low-speed driving, it is necessary to suppress the tendency of self-steer sensitivity and reduce the frequency of correction of the steering angle by the driver. If the self-supporting restoration device used is used, in addition to the gyro effect, it is possible to suppress the tendency of self-steering sensitivity due to the restoring force.
However, as described above, even if the motorcycle requires the above-described self-recovery device at low speed, the self-recovery device is not necessary because the straight-line performance increases due to the gyro effect at high speed. In addition, the restoring force suppresses the rotation of the handle, which hinders easy handle operation.
Therefore, in a motorcycle, the restoring force is easily changed according to the running state so that a restoring force is generated during low-speed driving and a light steering operation is possible without generating a restoring force during high-speed driving. This is not possible in the conventional example. In addition, although the adjustment valve is provided in the said prior art example, this adjustment valve is considered only for the internal pressure adjustment in an initial state, and it cannot change a restoring force with a driving | running | working state.
Therefore, the present invention aims to realize such a demand.

In order to solve the above-mentioned problem, the invention described in claim 1 attaches a steering system member (for example, the front wheel 2, front fork 7, handle 9, top bridge 11, etc. in the embodiment) to the vehicle body so as to be able to travel, In a vehicle having a restoring device that generates a force for returning the steering system member in the straight traveling direction between the vehicle body and the steering system member,
The restoration device includes a pressure chamber into which a high-pressure gas is injected,
Partitioning the pressure chamber into a plurality of chambers and rotating in conjunction with the handle;
A communication path communicating the plurality of partitioned compartments;
It is characterized by including a restoring force adjusting valve (for example, corresponding to the main valve 45 in the embodiment) that at least opens and closes the communication path.

According to a second aspect of the present invention, in the first aspect, the restoring force adjusting valve includes a valve side passage communicating with the communication passage, and the opening degree of the valve side passage is variable. .

According to a third aspect of the present invention, in the second aspect of the present invention, vehicle speed detection means (for example, the vehicle body speed sensor 72 of the embodiment corresponds) is provided, and the output thereof is higher than when the vehicle speed is high when the vehicle speed is low. It is characterized in that the restoring force is increased by reducing the opening of the restoring force adjusting valve.

According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the suspension detecting means (for example, the stroke sensor 62 of the embodiment) of the suspension (for example, the front fork 7 of the embodiment) is provided, and the output thereof is provided. Thus, when the stroke speed is large, the opening degree of the restoring force adjusting valve is made smaller and the restoring force is made larger than when the stroke speed is smaller.

According to a fifth aspect of the present invention, in any one of the second to fourth aspects, the steering system includes a steering angle detection means (e.g., corresponding to the steering angle sensor of the embodiment), and the steering angular velocity is determined by the output thereof. The restoring force is increased by reducing the opening degree of the restoring force adjusting valve when the steering angular velocity is slow when the speed is high.

According to the first aspect of the present invention, the communication passage that communicates the plurality of compartments defined in the pressure chamber is provided, and the communication passage is at least freely opened and closed by the restoring force adjusting valve. The gas moves freely between the two chambers, generating no restoring force and making the handle operation light.
Further, when the communication path is closed, the gas cannot move between the plurality of chambers, so that restoring force can be generated to reduce the wobbling of the handle.
Therefore, the restoring force of the restoring device can be easily adjusted by opening and closing the restoring force adjusting valve. If the restoring force adjusting valve is controlled to open and close according to the running state, the restoring force of the restoring device is adjusted according to the running state. it can.

According to the invention of claim 2, since the restoring force adjusting valve includes the valve side passage communicating with the communicating passage, and the opening degree of the passage is variable, by adjusting the opening degree of the restoring force adjusting valve, Various restoring forces can be adjusted.

According to the invention of claim 3, when the vehicle speed is low, the opening degree of the restoring force adjusting valve is made smaller and the restoring force is increased by the vehicle speed detecting means than when the vehicle speed is fast. You can make it harder to wobble by increasing the power. On the other hand, by reducing the restoring force at high speed, the steering feeling at high speed can be kept natural and the steering operation can be made light.

According to the fourth aspect of the present invention, it is possible to determine whether the road is a rough road or a good road based on the stroke speed based on the suspension stroke detection means. Therefore, when it is determined that the stroke speed is large and the road is rough, the opening of the restoring force adjustment valve can be made smaller and the restoring force can be increased than when the stroke speed is smaller. Can reduce the wobbling of the handle.

According to the fifth aspect of the present invention, the opening angle of the restoring force adjusting valve is reduced by the steering angle detecting means of the steering system when the steering angular velocity is fast, and the restoring force is increased compared to when the steering angular velocity is slow. By detecting the degree to which the steering wheel is swung from the steering angular velocity, the restoring force can be increased when the shaking speed is high, thereby suppressing the steering of the steering wheel.

Left side view of a motorcycle according to an embodiment. Perspective view of the restoration device and its vicinity Cross section of restoration device Configuration diagram of restoration device Diagram showing main valve position switching Position control table and graph showing the relationship between handle rotation torque and handle rotation angle at each position Operation explanatory diagram of the restoring device at the B position Operation explanatory diagram of the restoring device at the A position Flow chart of control method (first embodiment) Flow chart of control method (second embodiment)

FIG. 1 is a left side view of the motorcycle according to the present embodiment. The direction used in the present application is based on the vehicle. Specifically, in the state shown in FIG. 1, the front side in the left side / upper / perpendicular direction of the drawing is the front, upper, and left, respectively. This motorcycle supports a front wheel 2 and a rear wheel 3 before and after a body frame 1 and supports an engine 4 below the body frame 1 between the front wheel 2 and the rear wheel 3. A fuel tank 5 is supported above the engine 4 and a seat 6 is disposed behind the fuel tank 5.

The front wheel 2 is supported by a pair of left and right front forks 7, and each front fork 7 is rotatably supported by a head pipe 8 provided at the front end of the vehicle body frame 1 and is steered by a handle 9. The rotation of the handle 9 is controlled by the restoring device 10.

The restoring device 10 is mounted on a top bridge 11 for supporting the front fork 7 to the head pipe 8. A bottom bridge 12 is connected to the front fork 7 and the head pipe 8 together with the top bridge 11 below the top bridge 11.

Reference numeral 13 denotes a rear fork, the front end of which is swingably attached to the rear end of the vehicle body frame 1 and supports the rear wheel 3 at the rear end. The rear wheel 3 is chain driven, and a chain 16 is wound around the output sprocket 14 of the engine 4 and a driven sprocket 15 integrated with the rear wheel 3.

FIG. 2 is a perspective view of the restoring device 10 attached to the vehicle and the vicinity thereof as seen from an oblique direction of the vehicle.
The restoring device 10 is configured using an existing hydraulic steering damper, and is disposed in the vicinity of the top bridge 11 like the steering damper.
The top bridge 11 includes a horizontally long bridge body portion 11a and ring-shaped fork support portions 11b provided at both left and right ends thereof. A head pipe 8 is arranged between the bridge main body 11a and the center part of the bottom bridge 12 (not shown) in the left-right direction. The top bridge 11 and the bottom bridge 12 are connected to the top and bottom of the head pipe 8 by bolts 11c passed through the head pipe 8. Connected and integrated.

The bottom bridge 12 is the same member as the top bridge 11, and is provided with a fork support portion at both left and right end portions and a mounting portion (nut portion) of a bolt 11c at the center portion in the left and right direction.
The head pipe 8 is provided with a bearing of a bolt 11 c, and the top bridge 11 and the bottom bridge 12 connected by the bolt 11 c are rotatable with respect to the head pipe 8. The upper portions of the front forks 7 are passed through the fork support portions 11b, and the front forks 7 are fixed to the top bridge 11 and the bottom bridge 12 by splitting or the like.

The restoration device 10 includes a main body mechanism unit 20 that is a mechanism part for generating an air spring. The main body mechanism portion 20 includes an air spring case 21, and a mounting protrusion 22 that protrudes laterally from the air spring case 21 is fixed onto the front end flat portion 1 b near the head pipe 8 of the body frame 1 by a bolt 22 a. .
The air spring case 21 has a container shape opened upward, and is covered with a lid 28 to form a pressure chamber therein.

Further, between the air spring case 21 and the lid 28, a rotation shaft 23 having an axis line arranged in the vertical direction is supported so as to be rotatable around the axis line. The rotating shaft 23 is arranged substantially coaxially with the bolt 11c, and one end of the first link 24 is attached to the lower end of the rotating shaft 23. The other end of the first link 24 projects obliquely left frontward and above the bridge body 11a. The pin 25 is connected to one end of the second link 26.

The second link 26 is long in the left-right direction at the front center in the left-right direction of the bridge body 11a, and the other end opposite to the pin 25 is fixed onto the bridge body 11a by a bolt 27. Thereby, the rotation of the top bridge 11 is transmitted to the rotation shaft 23 via the first link 24 and the second link 26, and the rotation shaft 23 is synchronously rotated in conjunction with the top bridge 11. Yes.
As described above, when the rotation shaft 23 is connected to the top bridge 11 via the link mechanism, the lever ratio is increased compared with the case where the rotation shaft 23 is directly connected to the bolt 11c. The rotational torque transmitted to the moving shaft 23 can be increased.

FIG. 3 shows the configuration of the restoration device 10, where A is a cross-sectional view taken along line AA of C and B is a cross-sectional view taken along line BB of C. C is a cross-sectional view of the restoration device 10 corresponding to the CC line in A. FIG.
As shown in A, a fan-shaped pressure chamber 30 is provided in the air spring case 21, and the rotating shaft 23 is passed through a portion corresponding to the main part of the fan in the pressure chamber 30, and one end 23 a is air. The spring case 21 is rotatably fitted into a recess formed in the lid 28. The other end 23b of the rotation shaft 23 protrudes to the back surface of the air spring case 21, and is connected to one end of the first link 24 so as to be integrally rotatable.

A vane 31 is provided in the pressure chamber 30. One end of the pressure chamber 30 is integrated with the rotating shaft 23, and the vane 31 rotates integrally with the rotating shaft 23. The vane 31 is a movable partition that divides the inside of the pressure chamber 30 into a left chamber 32 and a right chamber 33, and the rotation shaft 23 and the opposite end 31a are arcuate walls of the pressure chamber 30 along the rotation locus circle. It is close to the inner peripheral surface of 30a.
The left chamber 32 and the right chamber 33 are variable volume chambers whose volumes are complementarily increased or decreased by the rotation of the vane 31.

The pressure chamber 30 is filled with high-pressure air in advance. When the high-pressure air is compressed in the rotation direction by the rotation of the vane 31, it functions as an air spring for generating a restoring force that prevents the vane 31 from rotating and pushes it back.
Accordingly, the high-pressure air on either the left chamber 32 or the right chamber 33 is compressed depending on the rotation direction of the vane 31.

However, as apparent from FIG. 3C, there is a predetermined gap 29 between the vane 31 and the inner wall of the pressure chamber 30, so that the left chamber 32 and the right chamber 33 communicate with each other through the gap 29. When the rotation speed (angular speed) of the pressure chamber is a relatively slow speed less than a predetermined speed, the high-pressure air in the pressure chamber 30 moves freely between the left chamber 32 and the right chamber 33 and is not compressed. This predetermined speed can be set freely.

The left chamber 32 is provided with a first outlet 32a and a first inlet 32b, and the right chamber 33 is provided with a second outlet 33a and a second inlet 33b.
The 1st discharge port 32a and the 2nd discharge port 33a are connected by the 1st communicating path 41 (A of FIG. 3).

The first communication passage 41 is provided with first check valves 41a and 41b between the first discharge port 32a and the second discharge port 33a, respectively. The first check valves 41a and 41b are arranged to allow only the outflow from the first discharge port 32a and the second discharge port 33a, respectively, and prevent backflow.

The 1st inflow port 32b and the 2nd inflow port 33b are connected by the 2nd communicating path 42 (A * C of FIG. 3). The second communication passage 42 is provided with second check valves 42a and 42b that prevent the outflow from the respective first inflow ports 32b and the second inflow ports 33b and enable the inflow (B in FIG. 3). ).
Furthermore, the third communication path 43 is connected to the second communication path 42, and the third communication path 43 is connected to the fourth communication path 44 and the first communication path 41.

These first to fourth communication passages are provided so as to be separated from each other in the thickness direction of the air spring case 21 (the axial direction of the rotation shaft 23), and have a so-called two-story structure. That is, the 1st communicating path 41 is formed in the upper layer shown to A of FIG. 3, and the 2nd-4th communicating paths 42-44 are formed in the lower layer shown to B of FIG.
However, the third communication path 43 and the fourth communication path 44 are connected to the first communication path 41 through a vertical communication path. The second communication path 42 is also connected to the first inlet 32b and the second inlet 33b through a vertical communication path, which is not visible in the drawing.

A main valve 45 is provided at an intermediate portion of the first communication passage 41 between the left and right first check valves 41a and 41b, and the movement of air between the left and right across the main valve 45 of the first communication passage 41 is blocked or communicated. It is designed to switch. This switching is performed by the linear solenoid 46.
The connecting portion of the third communication passage 43 to the first communication passage 41 is in the vicinity of the main valve 45.

The shutoff by the main valve 45 is a fully closed state that prohibits air movement between the left and right sides of the first communication passage 41 sandwiching the main valve 45, and prohibits movement of high-pressure air between the left chamber 32 and the right chamber 33. The communication includes a fully open state in which the air movement between the left and right is completely free, and a half open state in which a certain degree of restriction is imposed. The flow rate during half-opening can be freely set between fully closed and fully open. The switching of the main valve 45 is for adjusting the effectiveness of the air spring in the main body mechanism, and this adjustment is performed according to road surface determination (described later) according to the vehicle speed.

The fourth communication path 44 is provided with a relief valve 47. When the fourth communication path 44 becomes a predetermined air pressure or higher, the relief valve 47 is opened and high-pressure air is transferred from the first communication path 41 to the second communication path 42. It escapes and keeps air pressure below a predetermined level.

An accumulator 50 is connected to the second communication path 42 (B in FIG. 3). The accumulator 50 is an air pressure compensation device for the pressure chamber 30 and communicates with the left chamber 32 and the right chamber 33 via the second communication passage 42. When the air pressure in these chambers decreases to a predetermined level, the accumulator 50 High-pressure air is replenished to maintain the effectiveness of the air spring at a certain level.

The accumulator 50 divides the cylinder 51 into a high-pressure air chamber 53 and a spring chamber 54 with a slidable piston 52, connects the high-pressure air chamber 53 to the second communication passage 42, and fills the inside with high-pressure air. The spring chamber 54 accommodates a spring 55 and supports it with a predetermined set load.

The accumulator 50 can automatically compensate for the temperature change of the high-pressure air. When the temperature of the high-pressure air rises, the air pressure in the high-pressure air chamber 53 rises, so that the piston 52 resists the spring 55 as much as this rise. Then, the air pressure is maintained at a predetermined level by moving as indicated by an imaginary line and expanding the volume of the high-pressure air chamber 53 to eliminate the increase in the air pressure.

FIG. 4 is a configuration diagram of the restoration device 10. The restoration device 10 includes a main body mechanism unit 20, a control unit 60, a sensor unit 61, and a stroke sensor unit 62. The main body mechanism portion 20 is a mechanism portion for generating the above-described air spring, and the high-pressure air circuit is an equivalent circuit of the structure in FIG.
As shown in this equivalent circuit, when the first communication passage 41 is blocked by the main valve 45, the vane 31 rotates in conjunction with the rotation of the handle, so that a volume change occurs in the left chamber 32 and the right chamber 33. Even so, by prohibiting the movement of the high-pressure air between the left chamber 32 and the right chamber 33, the air pressure on the compression side is increased, a restoring force is generated by the air spring, and the handle is returned to the neutral position.

When the first communication passage 41 is communicated by the main valve 45, the movement of the high-pressure air between the left chamber 32 and the right chamber 33 is allowed, so that the vane 31 rotates in conjunction with the rotation of the handle, Even if volume changes occur in the left chamber 32 and the right chamber 33, the high-pressure air in the left chamber 32 or the right chamber 33 is not compressed so much, and a large air spring is not generated as in the case of interruption. It should be noted that the steering feeling can be kept natural because the steering wheel can be lightly steered with almost no air spring when fully opened. At the time of half-opening, some air springs can be generated to help maintain straightness.

The control unit 60 is a part that controls the linear solenoid 46 and includes an ECU 70 as a controller. The ECU 70 is supplied with power from the battery 71, and receives a vehicle body speed signal V from the vehicle body speed sensor 72 in the sensor unit 61, a front fork stroke signal ST from the stroke sensor unit 62, and a switch 73 for the entire device provided in the restoring device 10. Based on the ON / OFF signal, the position of the main valve 45 is determined and the linear solenoid 46 is driven and controlled. The vehicle speed sensor 72 can be shared with a vehicle speedometer.

The ECU 70 detects a stroke change at a predetermined time based on the stroke signal ST from the stroke sensor unit 62, calculates a stroke change per unit time as a stroke change speed, and uses this as a reference for road surface determination. 45 positions can also be determined.

FIG. 5 shows the position switching of the main valve 45. The main valve 45 includes a main body 45a, a spring 45b, and a ball 45c, and the opening degree of the valve-side passage 45d formed between the main body 45a and the ball 45c is changed by the amount by which the ball 45c is pushed into the main body 45a. ing.
The valve-side passage 45d communicates with the left and right portions of the first communication passage 41 sandwiching the main valve 45. When the opening of the valve-side passage 45d is changed, the movement of the high-pressure air in the first communication passage 41 is controlled. The restoring force can be adjusted by changing the generation of the air spring in the left chamber 32 or the right chamber 33.

In this example, the degree of opening change is such that the ball 45c is separated from the main body 45a and the valve cross-sectional area of the valve side passage 45d is maximized. The position is switched to one of the B positions in the fully closed state blocking 45d.
This position switching is performed by expansion and contraction of the actuator 46a of the linear solenoid 46. The expansion / contraction amount of the actuator 46 a is performed by the control drive of the linear solenoid 46 by the ECU 70.

FIG. 6 shows a control table A in this position switching, and B shows the relationship between the handle turning torque and the handle turning angle depending on the position.
In A, each position is determined based on the stroke (elongation) of the front fork 7 and the vehicle speed. That is, a threshold value is provided for each of the stroke and the vehicle speed, and a large threshold value ST1 and a small threshold value ST2 are set for the stroke. The vehicle speed is classified into low speed, medium speed, and high speed, and the boundary values are V1 and V2.

This means that rough roads can be determined based on the stroke change speed, which is the amount of stroke change per unit time. The state where the stroke change speed is large is a bad road, and the magnitude of the restoring force is determined according to the vehicle speed. It is based on the knowledge that it should be changed.

That is, when the stroke is larger than the large threshold value ST1 (ST> ST1), the stroke changing speed is also larger than the predetermined reference value, so that it is determined as a bad road. Otherwise, it is determined as a good road. When driving on rough roads, it is necessary to increase the restoring force.
However, even in the case of a good road determination, when the stroke is smaller than the small threshold value ST2 (ST <ST2), since the stroke change speed is small, the restoring force is not required, and this should be suppressed. In the middle, ST2 <ST <ST1 is a region that requires a certain degree of restoring force.

The large threshold value ST1 forms a straight line that changes to the right according to the vehicle speed, and the stroke amount of the threshold value ST1 increases as the vehicle speed increases. In general, even if the road surface is the same, the front fork stroke tends to increase as the vehicle speed increases. However, as the vehicle speed increases, straight travel increases, and the need for control to prevent staggering decreases. This is because there is a tendency.
The small threshold value ST2 also forms a straight line that changes to the right according to the vehicle speed. However, the inclination is smaller than ST1.

Further, the low speed range (V <V1) is a range in which the restoring force needs to be increased in order to reduce the wobbling during low speed running. On the contrary, in the high speed range, it is a range where it is necessary to suppress the restoring force and lighten the steering wheel operation.
The medium speed range is a range where it is desirable to generate a certain level of restoring force.

Therefore, ST> ST1 and the low speed region are B positions because they are regions that require a restoring force.
In ST <ST1 and above the medium speed range, the N position is set because it requires a certain level of restoring force.
However, in the case of ST <ST2 and the high speed range, the restoring force is not required, but rather the A position is set for the region where generation should be suppressed.
In this way, the control table for position determination is completed.

In addition, ST0 in the figure is a reference value of 1GST (stroke at the time of static load), and the vehicle body load is a standard value. Actually, 1GST changes due to a change in the loading amount due to a change in the number of passengers and the load amount. Therefore, if ST1 and ST2 are relative amounts based on ST0, correction is necessary due to the change in the loading amount.

Therefore, the state of the load capacity can be determined by the difference between the stroke at that time and (ST0) due to the change in the front fork stroke due to the change in the front and rear shared load at the time of static load, so the actual 1GST changes like a virtual line. For example, ST1 and ST2 can be corrected by this amount of change Δ if they are moved in parallel as indicated by virtual lines.

FIG. 6B shows the relationship between the handle rotation torque (vertical axis) and the handle rotation angle (horizontal axis) depending on the position. In general, the handle rotation angle and the handle rotation torque are correlated. In particular, in the present invention, since the air spring is involved, the proportional relationship between the handle rotation angle and the handle rotation torque changes depending on the position. In the A position, since no restoring force is generated by the air spring, the handle turning torque is reduced to be the straightest line a.

At the N position, a certain amount of restoring force is generated by the air spring to increase the torque, so that the handle turning torque is along the straight line n having a larger inclination than the straight line a. In this case, the setting is such that the change in the handle turning torque becomes smaller with respect to the change in the handle turning angle (the inclination of the straight line n is smaller than 45 °).

In the B position, it is along the straight line b having a steep angle greater than the straight line n (greater than 45 °), and the turning torque of the handle becomes larger than the turning angle of the handle. This is because a large restoring force is obtained by the air spring, and as a result, the wobbling of the handle is suppressed.

Next, the operation of the main body mechanism unit according to each position will be described.
FIG. 7 shows the operation of the B position in which the main valve 45 fully closes the first communication path 41, where A indicates a left turn and B indicates a right turn.
First, in A, when the handle 9 is turned to the left, the top bridge 11 is rotated counterclockwise, so that the rotation shaft 23 and the vane 31 are rotated counterclockwise via the second link 26 and the first link 24. Rotate.

Then, the high pressure air in the right chamber 33 is compressed by the vane 31 and becomes the high pressure side, and the left chamber 32 becomes the low pressure side due to capacity expansion.
At this time, the compressed high-pressure air in the right chamber 33 tends to flow out from the second discharge port 33a to the first communication passage 41. However, since the first communication passage 41 is closed by the main valve 45, 1 The valve is stopped by the main valve 45 after passing through the check valve 41b.

Further, since the second check valve 42b is exclusively used for inflow into the second inflow port 33b, the second inflow port 33b does not flow out from here to the second communication passage 42.
Therefore, since the high pressure air in the right chamber 33 cannot be moved to the left chamber 32 side and is compressed, a large air spring is generated, which becomes a large restoring force and pushes the vane 31 back to the neutral side. Is returned to the neutral position, so that the steering of the steering wheel 9 can be prevented to maintain straight running.

B indicates a right turn, and the vane 31 rotates clockwise, so that the left chamber 32 is on the high pressure side and the right chamber 33 is on the low pressure side.
As a result, the high-pressure air in the left chamber 32 tends to flow out from the first discharge port 32a to the first communication passage 41. However, since the first communication passage 41 is closed by the main valve 45, the first check valve 41a. Is stopped by the main valve 45.

Further, since the second check valve 42a is dedicated to the first inflow port 32b, the first inflow port 32b does not flow out from here to the second communication path 42.
Therefore, since the high-pressure air in the left chamber 32 is compressed without being moved to the right chamber 33 side, a large air spring is generated, and the vane 31 is pushed back to the neutral side. As a result, the handle is returned to the neutral position. It is possible to assist in maintaining straight running by preventing the steering wheel 9 from wobbling.

In both the right turn and the left turn, when the air pressure in the pressure chamber 30 falls below a predetermined level, the high pressure air is supplied from the accumulator 50 to the left chamber 32 or the right chamber 33 via the second check valve 42a or 42b. Replenish. Thereby, the pressure chamber 30 can maintain a predetermined air pressure and generate a large air spring.

At this time, the second check valve 42a or 42b allows the movement of the high-pressure air toward the first inlet 32b or the second inlet 33b of the left chamber 32 or the right chamber 33, respectively. Therefore, the accumulator 50 compensates for the air pressure fluctuation.

FIG. 8 is an operation explanatory view at the A position in which the main valve 45 fully opens the first communication path 41, where A indicates a left turn state and B indicates a right turn state.
During the left turn at A, the vane 31 rotates counterclockwise, and the right chamber 33 side becomes high pressure and the left chamber 32 side becomes low pressure.
Then, since the main valve 45 is opened and the first communication passage 41 is in a communication state, the high-pressure air in the right chamber 33 exits from the second discharge port 33a, passes through the first check valve 41b, and passes through the first check valve 41b. It flows out to the one communication passage 41. The high-pressure air that has flowed out into the first communication path 41 further enters the second communication path 42 from the third communication path 43. In the second communication path 42, the first check inlet 42 b passes through the low pressure side second check valve 42 a and enters the left chamber 32.

For this reason, the high pressure air flows in the order of the second discharge port 33a → the first communication path 41 → the third communication path 43 → the second communication path 42 → the first inlet 32b.
At this time, since the main valve 45 is sufficiently opened at the A position, high-pressure air smoothly flows from the right chamber 33 to the left chamber 32, and no air spring is generated. Reduce rotational torque.

B is when turning right, the vane 31 rotates clockwise, and the high-pressure air passes through the first check valve 41a from the first discharge port 32a, passes through the first communication passage 41, and passes through the third communication passage 43. To the second communication passage 42. Further, the air enters the right chamber 33 from the second inlet 33b through the second check valve 42b on the low pressure side. That is, the high-pressure air flows in the order of the first discharge port 32a → the first communication path 41 → the third communication path 43 → the second communication path 42 → the second inlet 33b, and almost the same air spring is generated as in the case of left turn. Therefore, the turning torque of the handle is reduced.
Note that the air pressure compensation by the accumulator 50 is performed in the same way as in the B position in both the left turn and the right turn.

Next, control of the linear solenoid 46 by the ECU 70 will be described with reference to the flowcharts of FIGS.
FIG. 9 shows the first embodiment. First, the linear solenoid 46 is set to the normal state (N position) (S1).
Subsequently, an on / off operation of the switch 73 is determined (S2). If the switch 73 is on (SW = ON), the linear solenoid 46 is driven to set the main valve 45 to the B position (S3). This is because the B position is basically set when the speed is not judged (see FIG. 6A).
If the switch 73 is off in S2, the process returns to S1 and waits for the switch 73 to be on.

Next, in S4, the road surface is determined by the stroke of the front fork. First, it is determined whether the stroke amount ST is smaller than a large threshold value ST1 (ST <ST1). If YES and the road surface determination based on the stroke change speed is a good road, the process proceeds to S5. When NO, that is, when ST> ST1 or bad road determination and ST> ST1 and bad road determination, the B position is maintained and the process returns to S2 (S4).

Subsequently, the vehicle speed V is compared with the threshold value V1 to determine whether V> V1. At this time, if V> V1, the vehicle is in the middle speed range and ST <ST1, and therefore matches the N position in the position table (A in FIG. 6). Therefore, the N position is determined and the main valve 45 is operated to switch to the N position (S6). If NO, V <V1 and the low speed range, so the position table is the B position, the B position is maintained, and the process returns to S4.

In S7 following S6, the stroke is compared with a small threshold value ST2, and if ST <ST2 (YES) and the road surface determination based on the stroke change speed is a good road, the position table is set to the A position. Since there is a possibility of corresponding, the process proceeds to S8. If NO, ST> ST2 or bad road determination or both, and corresponds to the N position or the B position in the position table, so the process returns to S4 while maintaining the N position.

S8 is a vehicle speed determination, and it is determined whether V> V2 whether the vehicle speed V is greater than a large threshold value V2. If YES, it is determined that the vehicle is in the high speed range. Since the position table corresponds to the A position, the process proceeds to S9, the main valve 45 is switched to the A position, then the process returns to S7, and the comparison of stroke and vehicle speed is repeated again.

If NO in S8, V <V2 and the speed is below the middle speed range, so the process returns to S4 to determine again whether the position is the N position or the B position. If YES here, the N position is maintained and S5 and subsequent steps are continued.
In the case of NO, it becomes a rough road judgment, and after returning to S2, it switches to the B position of S3, and the process below S4 is continued.

FIG. 10 shows a flowchart of the second embodiment in the ECU 70. In this embodiment, in the position determination, the magnitude of the steering angle is added to the stroke and the vehicle speed of the previous embodiment. The magnitude of the steering angle can be detected by a steering angle sensor, and the steering state of the steering wheel can be determined based on the detected value. The steering angle sensor is added to the sensor unit 61, and the detected value is sent to the ECU 70. The ECU 70 calculates a steering angular velocity that is a steering angle change amount per unit time based on the detected value. In addition, a limit angular velocity at which a predetermined or greater steering wheel shake should be limited is set in advance, and it is determined whether the limit angular velocity is within or exceeded the limit angular velocity, and the result is added to position determination.

The flowchart of FIG. 10 corresponds to the flowchart of FIG. 9, and S11 to 19 have the same contents except for S1 to 9 and S14 and 17 in the flowchart of FIG. Therefore, a different processing point will be described. First, S14 differs from the corresponding S4 in that it is determined by weighting whether or not the steering angular velocity is within the limit angular velocity, in addition to the comparison of stroke ST <ST1 and whether or not a good road is determined. For this reason, in this embodiment, even if the conditions of ST <ST1 and a good road determination are satisfied, if the steering angular velocity exceeds the limit angular velocity, the process does not proceed to S5 for position switching as in S4. , S12 is returned to maintain the B position.

S17 is also the same, and even if the condition of ST <ST2 and a good road determination is satisfied, if the steering angular speed exceeds the limit angular speed, the process does not proceed to S8 for position switching as in S7. Returning to S14, the N position is maintained or switched to the B position.
However, if the steering angular velocity is within the limit angular velocity in S14 and S17, the process proceeds to the next S15 and S18 as in S4 and S7, and the position switching from B → N or N → A is determined.

As described above, in this embodiment, the determination of whether or not the steering angular velocity is within the limit angular velocity is added to the position determination condition. Therefore, in addition to the determination of the ground contact state based on the stroke, it is possible to determine the steering state of the steering wheel. Thus, when the steering angular velocity is high, the opening degree of the main valve 45 can be reduced to B or N, and the restoring force of the steering wheel can be increased, compared to when the steering angular velocity is low. Therefore, the accuracy of the position switching control by adding the sensor can be improved, and the handle can be quickly restored by detecting the speed at which the handle is swung.

The present invention is not limited to the above-described embodiments, and various modifications and applications can be made within the principle of the invention.
For example, the structure of the main body mechanism unit 20 can be simplified, and the left chamber 32 and the right chamber 33 of the pressure chamber 30 are connected by a single communication path such as the first communication path 41 and restored in the middle. A force adjusting valve may be arranged to control the restoring force adjusting valve according to the running state. At this time, the restoring force adjusting valve may be merely opened / closed, or provided with an opening degree adjusting function in addition to opening / closing. In this way, the simplest steering restoration device can be realized.
Here, the restoring force adjusting valve is not limited to the main valve 45, and various known structures can be used. The adjusting drive is not limited to the linear solenoid 46, and various driving means can be used.

Further, the stroke speed may be calculated based on the stroke amount detected by the stroke sensor unit 62 such as the front fork 7 and the restoring force may be adjusted based on the stroke speed. In this case, when the stroke speed is fast, the restoring force is increased by reducing the opening of the restoring force adjusting valve than when the stroke speed is slow.
As described above, when the restoring force is adjusted based on the speed of the stroke instead of the size of the stroke, the bad road determination is made accurate based on the stroke speed, so that the restoring force control during the rough road traveling becomes more accurate.

In the embodiment, the high-pressure air filled in the pressure chamber 30 can be changed to another appropriate gas. If it is a compressible gas, it can function as a gas spring. However, high-pressure air is preferable because it is easy to handle and low in cost.
In addition, in the above embodiment, the position of the main valve is controlled in three stages, but a control table changed in two stages (that is, on / off) or four or more stages can be created.

Furthermore, as in another embodiment of FIG. 10, when another sensor for determining the state of the vehicle is added to the sensor unit 61 to increase the control accuracy, various sensors are possible, and a throttle opening sensor Can be used to determine the acceleration state. The same thing can be done with engine speed sensors and gear position sensors. Further, if a steering torque sensor is used, it is possible to determine a steering system input by a person from the driver side.

The above embodiment is based on the vehicle speed and the stroke of the front suspension (front fork), but the stroke of the rear suspension can be used instead of the front suspension. Furthermore, both the strokes of the front suspension and the rear suspension may be used. Further, acceleration may be sensed instead of the suspension stroke. These sensors constitute a stroke sensor unit 62.
In addition to sensing the steering angle of the steering, it is possible to improve the control accuracy by grasping the state of the steering system and performing feedback control.

This feedback control uses what knows the running condition such as throttle opening, engine speed, gear position information, etc., and what knows the force applied to the steering system by the person by the steering torque sensor. The accuracy can be increased.

10: Restoration device, 11: Top bridge, 20: Main body mechanism, 21: Air spring case, 30: Pressure chamber, 31: Vane, 32: Left chamber, 33: Right chamber, 41: First communication path, 42: First 2 communication paths, 43: 3rd communication path, 45: Main valve, 46: Linear solenoid, 50: Accumulator, 60: Control part, 61: Sensor part, 62: Stroke sensor part, 70: ECU

Claims (5)

In a vehicle in which a steering system member is movably attached to a vehicle body, and a restoring device (10) for generating a force for returning the steering system member in a straight traveling direction is interposed between the vehicle body and the steering system member.
The restoration device (10) includes a pressure chamber (30) into which a high-pressure gas is injected,
A partition wall (31) that divides the pressure chamber into a plurality of chambers (32, 33) and rotates in conjunction with the handle;
A communication path (41) communicating the plurality of partitioned chambers (32, 33);
A steering restoring device, comprising: a restoring force adjusting valve (45) that at least opens and closes the communication passage (41). The said restoring force adjusting valve (45) includes a valve side passage (45d) communicating with the communication passage (41), and an opening degree of the valve side passage is variable. Steering restoration device. The vehicle speed detection means (72) is provided, and the opening of the restoring force adjusting valve is made smaller when the vehicle speed is slow than when the vehicle speed is fast to increase the restoring force. Steering restoration device. A suspension detecting means (62) for the suspension (7) is provided, and its output reduces the opening of the restoring force adjusting valve (45) when the stroke speed is large and increases the restoring force when the stroke speed is small. The steering restoration device according to claim 2 or 3, wherein the steering restoration device is provided. A steering angle detection means for a steering system is provided, and the output of the steering system is such that when the steering angular velocity is high, the opening of the restoring force adjusting valve (45) is made smaller than when the steering angular velocity is slow, thereby increasing the restoring force. The steering restoring device according to any one of claims 2 to 4.

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